Modification of front-end loaders



p 0, 1969 D. J. 5. shown: 3,469,724

MODIFICATION OF FRONT-END LOADERS Filed Nov. 13, 1961 3 Sheets-Sheet 1 Sept. 30, 1969 D. J. 5. BROWN MODIFICATION OF FRONT-END LOADERS 3 Sheets-Sheet 2 Filed Nov. 15, 1967 Sept. 30, 1969 o. J. B. B ROWN 3,469,724

MODIFICATION OF FRONT-END LOADERS Filed Nov. 13, 1967 I 3 Sheets-Sheet 3 3,469,724 MODTFICATION F FRONT-END LOADERS David John Bowes Brown, Strand, England, assignor to Winger Limited, Rochester, Kent, England Filed Nov. 13, 1967, Ser. No. 682,484

Claims priority, application Great Britain, Nov. 14, 1966,

50,926/ 66 Int. Cl. EtlZf 3/62 US. Cl. 214-776 4 Claims ABSTRACT 9F THE DISCLGSURE There is provided an improved construction for a front-end loader wherein a single beam is pivotally mounted to a chassis so as to be raised or lowered. At the forward end of the beam is mounted a working member such as a bucket or scraper. An inter-lever has one end mounted to the beam intermediate the ends of the beam, with a cranked lever connected to the interlever intermediate its ends and a forward crowbar connecting the free end of the inter-lever with the bucket. The geometry of the linkages of the beam with respect to the chassis is such that movement of the beam during the raising or lowering of the bucket or scraper has a roll-back of five degrees at maximum out-reach of the beam and returns to the initial position as the outreach diminishes toward the maximum height.

The present invention relates to leaders for handling materials, e.g. earth, and more particularly to front-end loaders such as, for example, tractor shovels.

In known construction of front-end loaders there is a beam composed of a pair of spaced side members which are mounted to have pivotal movement with respect to a chassis whereby the beam may be raised or lowered, and at the forward end of the beam there is a mounting for a bucket or scraper. With such constructions it is necessary to provide a number of pivotal points and couplings in order to provide the necessary linkages for the raising or lowering of the beam and to move or roll back the bucket or scraper to the required positions. At the same time, it is necessary to provide further pivot points and couplings for hydraulic rams which are generally used to raise or lower the beam.

In some constructions the number of pivot points and couplings varies from 14 to 24 all of which require frequent maintenance and inspection.

Where a bucket is employed it is necessary that it may be moved from a loading or pick-up position to a carry or lifting position so that the contents do not spill from the bucket. Also, it is necessary to ensure that the bucket does not tilt forward or backwards in relation to the horizontal during the raising or carrying operation.

It is among the objects of the present invention to overcome or reduce these disadvantages.

The present invention provides a loader comprising a chassis, a beam having one end for pivotal connection to the chassis of the loader to permit movement of the other or free end of the beam in a vertical plane, a mounting at the free end of the beam for a bucket or scraper, a pivotal connection for one end of a hydraulic ram and one end of a link arm intermediate the ends of the beam, a link pivotally mounted between the bucket or scraper and the free end of the link arm, a cranked lever mounted intermediate its end about the same mounting as the beam to the chassis, a link extending between one end of the cranked lever and a position intermediate the ends of the link arms, one end of a further hydraulic ram pivotally connected to the free end of the link arm,

and mountings on the chassis for the free ends of the hydraulic rams.

Preferably the beam is of two-part construction, having an upper and a lower member and reinforcing members extending from one of the members from regions of reduced stress which contact the other member. The two members of the beam may be interconnected by welding lines extending around the periphery of the beam.

The geometry of the linkages of the beam with respect of the chassis may be such that movement of the beam during the raising or lowering of the bucket or scraper has a roll back of 5 at maximum out-reach of the beam and returns to the initial position as the out-reach diminishes towards the maximum height to which the bucket or scraper is raised, thus compensating for static and dynamic tyre deflections predominantly of a nose down or bucket tipping motion which is accentuated when the beam is substantially in the maximum out-reach position. For example, where a bucket is filled in a manner of a shovel by pushing the bucket into the material to be moved, it is necessary to roll the bucket through an angle of 45 to retain the material and on raising of the beam the bucket moves from the initial 45 roll back to 50 at the maximum out-reach and returns to the 45 position at the maximum height of lift.

The invention will now be described by way of example with reference to the accompanying drawings, in which:

FIGURE 1 is a diagrammatic view showing the loader according to the present invention;

FIGURE 2 is a front view of the constructions shown in FIGURE 1;

FIGURE 3 is a diagrammatic side view on an enlarged scale showing component parts of the construction of FIGURE 1; and

FIGURE 4 is a plan view of FIGURE 3.

In the drawings there is shown a loader having a chassis from which projects on its upper forward surface a support member 2 for a main beam 3. This support member is stepped intermediate its height to provide a backwardlyslanting projection 4. A drivers cab 5 and the radiator 6 for the engine of the loader are mounted on opposite sides of the support member 2. The main beam 3 is constructed from an upper and lower member 10, 11 which are formed by pressings. Within the upper member 10, at points which have low areas of stress there are welded components (not shown) which project so that when the upper member 10 is placed with respect to the lower member 11, the free surfaces of the welded components lie in close proximity with the inner surface of the lower member 11. The upper and lower members 10 and 11 are constructed with close tolerance so that when one rests within respect of the other the sides of one overlaps the sides of the other member. The members are welded together by lines of welding 15 which extend along the edge of the overlap of the sides. Preferably such welding extends in a low stress area in proximity to the neutral axis of the beam.

Each end of the main beam 3 provides spaced apart longitudinally-extending side arms 16, 17 respectively and each arm 16, 17 is provided with a bearing member 18, 19 respectively at its extremity. Intermediate the ends of the main beam 3 is an elongated aperture 20 which extends through the beam 3 and each of the longitudinal sides 21, 22 defining the aperture 20 of the beam in the vicinity of the aperture has a bore provided with a bearing member 25. The axes of the bearing members 25 are parallel to the axes of the bearing members 18, 19 at each of the ends of the main beam 3.

The bearing members 19 in the side arms 17 at one end of the main beam 3 are located in alignment with a bore having a bearing member (not shown) in the step portion of the upwardly-projecting chassis structural member 2 on the chassis 1 by bearing shafts 28a and 28c. A cranked lever 29 is mounted intermediate its ends on a bearing shaft 28 located in the chassis structure between the side arms 17. A shaft 30 extends between the bearings 25 in the sides 21, 22 of the beam 3 defining the elongated aperture 20 and carries pivotally a ram head 32 of a hydraulic ram 33 and on each side of the ram head 32 are mounted the side arms of a lever or interlever 34. The body of the hydraulic ram 33 is pivotally connected to a mounting 36 on the lower part of the upwardly-projecting member 2 of the chassis 1. Bearings 38 are provided intermediate the ends of the lever 34 and one end of a rear link 39 is connected between the bearings 38 by a shaft 40, the other end of the link 39 extends to the upper end of the cranked lever 29 where it is pivotally interconnected to a bearing 41 by a shaft 42. The lower end of the cranked lever 29 is forked and carries a bearing 44 in each fork arm and a shaft 45 passing through the bearings 44 engages a coupling of a ram head 46 of a second hydraulic ram 47. The body of the hydraulic ram 47 is connected to the upper end of the rearwardly-projecting member 4 by a shaft 48 passing through bearings 49 in the member 4 and a bearing (not shown) in the end of the body of the hydraulic ram 47.

The free end of the main beam 3 carries between the side arms 16 a work member 50 such as a bucket or scraper which is retained in position by bearing rods 51 extending between the bearing members 18 in the ends of the side arms 16 and corresponding bearing supports (not shown) in the load carrying outer rear flanges of the bucket 50 disposed on each side of the side arms 16. A crowd bar 58 is pivotally connected to a bearing member 57 in central load carrying rear flanges of the bucket on each side of the crowd bar. The crowd bar 58 is pivotally connected to the free end of the lever 34 by a shaft 60 passing through bearings 61 in the crowd bar 58 and the lever 34.

When in use, with the main beam 3 in the lowered position (as shown) the forward end of the bucket 50, which generally has a toothed edge 66, lies in close proximity to the surface over which the loader is to be moved and on forward movement of the loader the toothed edge 66 of the bucket 50 digs into the pile of material to be moved. When the bucket 50 is full it is tilted or moved through 45 with respect to the horizontal, by means of the ram head 46 of the second ram 47 acting on the cranked lever 29 and transmitting movement by rear link 39 to lever 34 which in turn operates the crowd bar 58 connected to the bucket 50. To raise the bucket 50 and contents the ram head 32 of the other hydraulic ram 33 connected between the chassis 1 and the beam 3 is operated so that the ram head 32 is extended from the housing of the ram 33 to exert a pressure below the beam 3 whereby the beam 3 and the bucket 50 are raised in an upward direction. The linkage between the bucket 50 and the cranked lever 29 is such that during this movement the bucket 50 moves from the initial 45 with respect to the horizontal to a roll back position at 50 with respect to the horizontal position at the point of maximum outreach, i.e. forward extent of the main beam 3, and moves back to the original 45 with respect to the horizontal as the outreach diminishes on further movement of the main beam to the maximum height of lift.

When it is required to empty the bucket 50 this may be accomplished at any height within the arc of movement of the main beam by simply operating the hydraulic ram 47 so that due to the linkage the crowd bar 58 is moved to roll the bucket 50 forward and spill the contents.

The linkage between the bucket 50 and the ram 47 for operating the bucket is so arranged that the cranked lever 29 which is pivotally mounted by the shaft 28, reaches a position that is in line with the centre line of the intermediate link 34 when the bucket 50 is fully tipped with the main beam 3 above the horizontal position, thus causing a rotational deceleration of the tipping bucket 50 as the links 29 and 34 are forced into parallelism with one another and a top dead centre condition is reached between these two links, thus reducing dynamic loads imposed on the bucket linkage under these conditions and reducing residual energy to be absorbed by bucket tipping stops.

With this construction, the mounting points for the bucket 50 and beam 3 are considerably reduced in number relative to the number in conventional loaders and by mounting the drivers cab 5 to one side of the main beam 3 the overall height can be reduced. The height of the radiator 6 can be reduced with a consequent improvement of rearward visibility and furthermore, the cooling of the machine can be considerably improved by the mounting of the engine and transmission radiators for the vehicle on the opposite side of the main beam to the drivers cab thereby enabling cooling advantages to be obtained when running between operational sites from the ram effect of the airstream and the improved efliciency of a suction radiator fan which would have its performance reduced in a rearward facing radiator installation, as in a conventional machine, due to the reduced air pressure that would occur in this region when travelling at high speed.

Reference has been made to the bucket being used for transferring material from one place to another but it is possible for the leading or toothed edge of the bucket to act as a jack for the vehicle by moving the bucket so that it digs into the ground or surfaces over which the loader moves and on further movement of the hydraulic ram it is possible for the beam and bucket to exert a pressure so that the front axle of the tractor is raised. This is particularly advantageous in the event of the wheels of the tractor failing to provide a gripping surface, such as in deep mud or similar circumstances. The main beam linkage also achieves greater tipping angles of a bucket than linkages in general use. For example, the bucket can be tipped to a position where the flat of the bucket blade is at right angles to the horizontal to permit grading operations to be effectively discharged.

The present invention provides a machine configuration which facilitates the incorporation of a chassis structure that can provide a greater strength for structural connections between the beam and pivotal mountings because of the absence of the cab and associated driving control, which would normally be in this region with the more general types of loading shovel construction. Furthermore, greater freedom is provided than with the more normal form of loading shovel construction for the provision of different types of lifting beams and mechanism and other forms of interchangeable equipment because movable structures in this region will not materially deteriorate from the drivers visibility as would be the case if the cab was centrally positioned.

As will be appreciated the lifting beam of the invention is a homogeneous or box type fabrication generally able to provide greater stiffness and strength than would be the case with the more usual form of double beam and cross bracing that is necessary in common shovel loader configurations that necessitate this form of structure, to avoid deterioration of the drivers visibility.

Furthermore, the side location of the drivers cab permits a view to be obtained of the side of the bucket or scraper and thus enables a more accurate control to be obtained of the bucket or scraper and enables the vehicle to be accurately steered in relation to side obstructions which would not be the case with a more conventional central cab position as the back of the bucket or scraper blade would mask the visibility of the cutting edge or the side of the bucket or scraper or wheels in relation to a side obstruction.

In the above example reference has been made to the beam being located at the front of the loader but the beam may extend from the rear of the loader.

What I claim is:

1. A loader comprising a chassis, a single beam having one end for pivotal connection to the chassis of the loader to permit movement of the other or free end of the beam in a vertical plane, a mounting at the free end of the beam for work member, a pivotal connection for one end of a hydraulic ram and one end of a link arm intermediate the ends of the beam, a link pivotally mounted between the work member and the free end of the link arm and skewed relative to said beam, a cranked lever mounted intermediate its end about the same mounting as the beam to the chassis, a link extending between one end of the cranked lever and a position intermediate the ends of the link arm and skewed relative to said beam, one end of a further hydraulic ram pivotally connected to the free end of the link arm, and mountings on the chassis for the free ends of the hydraulic rams.

2. A loader as claimed in claim 1 in which linkages of the beam with respect to the chassis is such that the movement of the beam during the raising or lowering of the work member has a roll-back of 5 at maximum outreach of the beam.

3. A loader as claimed in claim 2, in which the work member returns to the initial position as the out-reach diminishes to the maximum height to which the work member is raised.

4. A loader as claimed in claim 3, comprising a drivers cab and a radiator for a motor mounted respectively on each side of the support member.

References Cited UNITED STATES PATENTS 1,917,666 7/1933 Russell 214-145 2,668,631 2/1954 Reese 214-776 X 3,088,611 5/1963 Holdren 214776 3,184,086 5/1965 Lull 214-776 X 3,254,780 6/1966 Midtbo 214145 X GERALD M. FORLENZA, Primary Examiner 

